沙子都到哪兒去了

Why Sand Is Disappearing

沙子都到哪兒去了

BERKELEY, Calif. — TO those of us who visit beaches only in summer, they seem as permanent a part of our natural heritage as the Rocky Mountains and the Great Lakes. But shore dwellers know differently. Beaches are the most transitory of landscapes, and sand beaches the most vulnerable of all. During big storms, especially in winter, they can simply vanish, only to magically reappear in time for the summer season.

加利福尼亞伯克利——對于只在夏天去海邊游玩的人來說，海灘仿佛是一種永久的自然遺產(chǎn)，就像落基山脈和五大湖一樣。然而，住在海邊的人知道，事實并非如此。海灘是最容易轉瞬即逝的地貌，而沙灘又是其中最為脆弱的一種。遇到大風暴，尤其是在冬天，它們會消失，待到來年夏季將至的時候又會神奇地及時重現(xiàn)。

It could once be said that “a beach is a place where sand stops to rest for a moment before resuming its journey to somewhere else,” as the naturalist D. W. Bennett wrote in the book “Living With the New Jersey Shore.” Sand moved along the shore and from beach to sea bottom and back again, forming shorelines and barrier islands that until recently were able to repair themselves on a regular basis, producing the illusion of permanence.

博物學家D·W·本內(nèi)特(D. W. Bennett)在《與新澤西海灘共度時光》(Living With the New Jersey Shore)一書中寫道，“海灘是沙子在繼續(xù)前往別處之前停留片刻的地方。”曾幾何時，的確可以這么說。沙子沿著水岸運動，從灘涂到海底再到灘涂，塑造了海岸線和堰洲島。直到不久前，這些地貌還能經(jīng)常自我修復，制造出一種永恒的假象。

Today, however, 75 to 90 percent of the world’s natural sand beaches are disappearing, due partly to rising sea levels and increased storm action, but also to massive erosion caused by the human development of shores. Many low-lying barrier islands are already submerged.

然而今天，世界上75%到90%的自然沙灘正在消失。部分原因在于海平面上升和風暴活動增加，但更重要的是，人類對海灘的開發(fā)造成了大規(guī)模的侵蝕。許多地勢較低的堰洲島已經(jīng)被海水淹沒。

Yet the extent of this global crisis is obscured because so-called beach nourishment projects attempt to hold sand in place and repair the damage by the time summer people return, creating the illusion of an eternal shore.

可是，由于所謂的“人工育灘”計劃，這一全球性危機的嚴重程度遭到了忽視。這些工程努力在夏季游客到來之前將沙子留在原處并修復損失，制造出一種海灘永在的幻象。

Before next summer, endless lines of dump trucks will have filled in bare spots and restored dunes. Virginia Beach alone has been restored more than 50 times. In recent decades, East Coast barrier islands have used 23 million loads of sand, much of it mined inland and the rest dredged from coastal waters — a practice that disturbs the sea bottom, creating turbidity that kills coral beds and damages spawning grounds, which hurts inshore fisheries.

下個夏天到來之前，看不到盡頭的自卸車隊會運來材料填補裸露的地表并修復沙丘。光是弗吉尼亞海灘，就被恢復了逾50次。近幾十年里，美國東海岸的堰洲島用掉了2300萬車的沙子，其中許多采自陸地，其余則從沿海水域挖掘。挖沙的做法會干擾海床，產(chǎn)生不利于珊瑚礁生存并會破壞生物繁殖地的渾濁海水，從而損害近海漁業(yè)。

The sand and gravel business is now growing faster than the economy as a whole. In the United States, the market for mined sand has become a billion-dollar annual business, growing at 10 percent a year since 2008. Interior mining operations use huge machines working in open pits to dig down under the earth’s surface to get sand left behind by ancient glaciers. But as demand has risen — and the damming of rivers has held back the flow of sand from mountainous interiors — natural sources of sand have been shrinking.

砂石行業(yè)的增長如今比整體經(jīng)濟更為迅猛。在美國，開采出來的沙子已形成了每年上十億美元的市場規(guī)模，2008年以來的年增長率為10%。內(nèi)陸采砂采用大型機械露天作業(yè)，挖開地表，以便開采出古老冰川留下的砂石。不過，隨著需求的增加，以及在水上修建大壩的行為阻止了泥沙從多山的內(nèi)陸地區(qū)向外的遷移，砂石自然資源一直在縮減。

One might think that desert sand would be a ready substitute, but its grains are finer and smoother; they don’t adhere to rougher sand grains, and tend to blow away. As a result, the desert state of Dubai brings sand for its beaches all the way from Australia.

人們或許會認為，來自沙漠的沙子應當是現(xiàn)成的替代品。但實際上，這種沙粒更細、更光滑，不能與較為粗糙的沙粒黏合，而且容易被吹走。因此，沙漠之國迪拜需要為了本地的海灘萬里迢迢從澳大利亞進口沙子。

And now there is a global beach-quality sand shortage, caused by the industries that have come to rely on it. Sand is vital to the manufacturing of abrasives, glass, plastics, microchips and even toothpaste, and, most recently, to the process of hydraulic fracturing. The quality of silicate sand found in the northern Midwest has produced what is being called a “sand rush” there, more than doubling regional sand pit mining since 2009.

現(xiàn)在出現(xiàn)了海灘用沙的全球性短缺，而導致這種短缺的是越來越依賴砂石的各大行業(yè)。沙子是生產(chǎn)磨料、玻璃、塑料、微芯片乃至牙膏的關鍵用料，最近還成為水力壓裂工藝中不可或缺的一環(huán)。美國中西部北面發(fā)現(xiàn)的硅砂在當?shù)叵破鹆艘还?ldquo;淘沙熱”，使得該地區(qū)的沙坑開采活動自2009年以來翻番有余。

But the greatest industrial consumer of all is the concrete industry. Sand from Port Washington on Long Island — 140 million cubic yards of it — built the tunnels and sidewalks of Manhattan from the 1880s onward. Concrete still takes 80 percent of all that mining can deliver. Apart from water and air, sand is the natural element most in demand around the world, a situation that puts the preservation of beaches and their flora and fauna in great danger. Today, a branch of Cemex, one of the world’s largest cement suppliers, is still busy on the shores of Monterey Bay in California, where its operations endanger several protected species.

不過，所有工業(yè)生產(chǎn)中耗沙量最大的是混凝土行業(yè)。自19世紀80年代以來，來自長島華盛頓港的砂石——1.1億立方米——一直在為曼哈頓的通道和路面建設貢獻力量。采砂業(yè)的80%產(chǎn)量目前依然流向了混凝土行業(yè)。除了水和空氣，沙子是全球范圍內(nèi)需求量最大的自然產(chǎn)物。這一現(xiàn)狀威脅到了對海灘和生長在其中的動植物進行保護的工作。就在當下，世界最大的水泥供應商之一西麥斯集團(Cemex)旗下的一家分公司，仍然在加州蒙特雷灣的海灘積極采砂，危及到了數(shù)種保護物種。

The huge sand mining operations emerging worldwide, many of them illegal, are happening out of sight and out of mind, as far as the developed world is concerned. But in India, where the government has stepped in to limit sand mining along its shores, illegal mining operations by what is now referred to as the “sand mafia” defy these regulations. In Sierra Leone, poor villagers are encouraged to sell off their sand to illegal operations, ruining their own shores for fishing. Some Indonesian sand islands have been devastated by sand mining.

全球范圍內(nèi)興起的大型采砂活動中，許多都屬非法行為，但它們并未進入發(fā)達國家的視野，也未被放在心上。不過在印度，政府已出手限制在海岸附近采砂，但那些已被人稱為“采砂黑手黨”的非法開采集團對這些監(jiān)管規(guī)定視而不見。在塞拉利昂，貧困村民受到鼓勵，要將沙子賣給非法企業(yè)，從而徹底破壞了當?shù)氐慕２遏~環(huán)境。一些印度尼西亞的沙島因采砂而遭遇重創(chuàng)。

It is time for us to understand where sand comes from and where it is going. Sand was once locked up in mountains and it took eons of erosion before it was released into rivers and made its way to the sea. As Rachel Carson wrote in 1958, “in every curving beach, in every grain of sand, there is a story of the earth.” Now those grains are sequestered yet again — often in the very concrete sea walls that contribute to beach erosion.

是時候讓我們了解沙子的來源和去向了。它曾被困在山上的巖石里，經(jīng)過億萬年的侵蝕才得以進入山川河流，然后來到海里。正如蕾切爾·卡森 (Rachel Carson)1958年寫下的那樣，“在每個蜿蜒的海灘，在每顆沙粒之中，都藏有大地的故事。”現(xiàn)在，這些沙礫卻再次受困——往往就在那些助推海灘侵蝕的混凝土防波堤里。